BUG#35549008 Classic session does not report errors in stored procedures

Classic sessions were not validating result errors when fetching multiple results,
i.e. in calls to stored procedures,  this prevented the errors from being properly reported

Change-Id: I1fa57ebef1d60b5fa302c0f96dbf90292088f8eb

Author: rennox

mysqlshdk/libs/db/mysql/session.cc

@@ -700,7 +700,14 @@ static void free_result(T *result) {
 bool Session_impl::next_resultset() {
   if (_prev_result) _prev_result.reset();
 
-  return mysql_next_result(_mysql) == 0;
+  int rc = mysql_next_result(_mysql);
+
+  if (rc > 0) {
+    throw Error(mysql_error(_mysql), mysql_errno(_mysql),
+                mysql_sqlstate(_mysql));
+  }
+
+  return rc == 0;
 }
 
 void Session_impl::prepare_fetch(Result *target) {

unittest/scripts/auto/js_devapi/scripts/stored_procedure_calls_norecord.js

@@ -27,4 +27,23 @@ session.runSql("call multiupdates();");
 
 session.runSql("drop schema bug29451154");
 
+//@<> Test stored procedure error is properly reported
+shell.connect(__uripwd);
+session.createSchema("bug35549008");
+session.runSql("CREATE PROCEDURE  bug35549008.my_sp_with_error() BEGIN SELECT 1; SELECT * FROM UNEXISTING; SELECT 2; END;")
+
+// Tests Classic Protocol
+shell.connect(__mysqluripwd + "/bug35549008");
+session.runSql("call my_sp_with_error()")
+EXPECT_OUTPUT_CONTAINS("ERROR: 1146: ClassicResult.dump: Table 'bug35549008.UNEXISTING' doesn't exist");
+WIPE_OUTPUT()
+
+// Tests X Protocol
+shell.connect(__uripwd + "/bug35549008");
+session.runSql("call my_sp_with_error()")
+EXPECT_OUTPUT_CONTAINS("ERROR: 1146: SqlResult.dump: Table 'bug35549008.UNEXISTING' doesn't exist");
+WIPE_OUTPUT()
+
+session.runSql("drop schema bug35549008");
+
 session.close();